//Sample_21_16.java
import java.io.Console;
public class Sample_21_16 {

    private static Console cons = System.console();

    public static Boolean getBoolean(String msg){

        Boolean yes = null;
        char ch = ' ';

        String str = cons.readLine(msg);
        if(str.length() != 0){
            ch = str.charAt(0);
        }

        if(ch=='y' || ch=='Y' || ch=='n' || ch=='N'){
            yes = ch!='n' && ch!='N';
        }

        return yes;
    }

    public static void main(String[] args) {

        int floor = 1;

        boolean bool = getBoolean("Do you go up the stairs? (y/n): ");
        System.out.println("echo : " + bool);

        if(bool){
            floor++;
            System.out.println("Went up to the " + floor + " floor");
        }else{
            System.out.println("On the " + floor + " floor");
        }
    }
}